Title :
Magnetic flux distribution dynamics in Bi-2223/Ag tapes
Author :
Paasi, Jaakko ; Lahtinen, Markku ; Eriksson, Jarl-Thure ; Sarkaniemi, Jyrki
Author_Institution :
Lab. of Electr. & Magnetism, Tampere Univ. of Technol., Finland
fDate :
7/1/1994 12:00:00 AM
Abstract :
We have studied magnetic flux distribution dynamics in silver sheathed Bi-2223 superconducting tapes at 77 K using a novel Hall sensor technique. The flux distribution exhibits a strongly time dependent behaviour due to thermally activated flux creep in the intergranular current system. In applied constant fields the decrease of measured magnetic field profiles was due to a logarithmic relaxation in time of induced intergranular screening currents. In slowly swept AC magnetic fields the flux distribution dynamics was governed by a continuous relaxation of intergranular screening currents. The screening current density was logarithmically dependent on the sweep rate of the applied field
Keywords :
bismuth compounds; calcium compounds; composite superconductors; flux creep; high-temperature superconductors; lead compounds; magnetic flux; silver; strontium compounds; 77 K; Ag sheathed Bi-2223 superconducting tapes; Bi-2223/Ag tapes; BiPb2Sr2Ca2Cu3O-Ag; Hall sensor technique; applied constant fields; induced intergranular screening currents; intergranular current system; logarithmic relaxation; magnetic flux distribution dynamics; measured magnetic field profiles; slowly swept AC magnetic fields; thermally activated flux creep; time dependent behaviour; Annealing; Conducting materials; Creep; Magnetic field measurement; Magnetic flux; Materials science and technology; Silver; Superconducting films; Superconducting magnets; Superconductivity;
Journal_Title :
Magnetics, IEEE Transactions on
